Effects of coffee on ambulatory blood pressure in older men and women - A randomized controlled trial

This study assessed the effects of regular coffee drinking on 24-hour ambul atory blood pressure (ABP) in normotensive and hypertensive older men and w omen. Twenty-two normotensive and 26 hypertensive, nonsmoking men and women , with a mean age of 72.1 years (range, 54 to 89 years), took part in the s tudy. After 2 weeks of a caffeine-free diet, subjects were randomized to co ntinue with the caffeine-free diet and abstain from caffeine-containing dri nks or drink instant coffee (5 cups per day, equivalent to 300 mg caffeine per day) in addition to the caffeine-free diet for a further 2 weeks. Chang e in systolic and diastolic blood pressures (SBP, DBP) determined by 24-hou r ambulatory BP monitoring showed significant interactions between coffee d rinking and hypertension status. In the hypertensive group, rise in mean 24 -hour SEP was greater by 4.8 (SEM, 1.3) mm Hg (P=0.031) and increase in mea n 24-hour DBP was higher by 3.0 (1.0) mm Hg (P=0.010) in coffee drinkers th an in abstainers. There were no significant differences between abstainers and coffee drinkers in the normotensive soup for 24-hour, daytime, or night time SEP or DBP. In older men and women with treated or untreated hypertens ion, ABP increased in coffee drinkers and decreased in abstainers. Restrict ion of coffee intake may be beneficial in older hypertensive individuals.